02 Yukon making awful noise!!

[Chubbs]

@Malibu907

I saw a video clip last year that included the same noise, I think same truck. he had all 4 wheels off the ground and it came from the transfer case. He called the sound "gravel tumbling" or something. Drain the case & see what comes out. Here it is::

Did you ever put the transfer case into "neutral?" That could probably isolate any noise between the trans & transfer case. The owners manual has directions for this if you have never performed the operation.

 

[Malibu907]

Have you checked the transfer case fluid? It could be the chain in the TCASE. Also, check your the parking brake...those shoes fall apart sometimes and make all sorts of racket. Noises in these rigs tend to travel, and unless you have someone running next to your truck listening while it's rolling, can be hard to locate exact source. Just some other ideas to look at. Good luck.

We did literally run next to it. I thought it was the e brake also. We finally jacked up the back end and it is most definitely the transfer case

 

[Malibu907]

@Malibu907

I saw a video clip last year that included the same noise, I think same truck. he had all 4 wheels off the ground and it came from the transfer case. He called the sound "gravel tumbling" or something. Drain the case & see what comes out. Here it is::

Did you ever put the transfer case into "neutral?" That could probably isolate any noise between the trans & transfer case. The owners manual has directions for this if you have never performed the operation.

It doesn't sound like gravel tumbling but close mine has a thump along with it. It is definitely the transfer case and I am draining the fluid today. This is kinda mind boggling. I'm surprised that the tranny shop automatically went to the tranny when the tranny isn't making noise at all. I'm a little bitter about that. O am a little out of my element with a transfer case issue but ill see what I can do today to figure out what went wrong. A friend of mine thinks its a solenoid stuck in the transfer case.

 

[M1Gunner]

Just heard the video and transfer case!!!

 

[Chubbs]

A solenoid?!?! hate to tell you but there is no solenoid in there. that would be waaay too easy. there is a motor on the outside of it but everything inside is mechanized like shafts/gears/chain.

before you drain the oil, remove the filler plug and get a reading on the current fill-level. when you drain it, set the oil aside and measure the capacity compared to the 2-liters that is the spec capacity.

is there any evidence of an oil leak? look specifically at the top of the tailshaft (rear output) as this is the usual location of "pump rub" where the oil pump retainer clips break off and scribe through the case, allowing the oil to escape and run low, thereby resulting in catastrophic damage.

before you split the case halves you can inspect the contents you have drained into a clear or glass container. run a magnet through it to collect the metals. should be a good indicator of the rebuild level. anything from a bearing/seal refresh to a full overhaul of planetary/clutch/chain. you might be in the market for a lightly-used replacement if it comes to that. depends on your preference.

 

[Malibu907]

A solenoid?!?! hate to tell you but there is no solenoid in there. that would be waaay too easy. there is a motor on the outside of it but everything inside is mechanized like shafts/gears/chain.

before you drain the oil, remove the filler plug and get a reading on the current fill-level. when you drain it, set the oil aside and measure the capacity compared to the 2-liters that is the spec capacity.

is there any evidence of an oil leak? look specifically at the top of the tailshaft (rear output) as this is the usual location of "pump rub" where the oil pump retainer clips break off and scribe through the case, allowing the oil to escape and run low, thereby resulting in catastrophic damage.

before you split the case halves you can inspect the contents you have drained into a clear or glass container. run a magnet through it to collect the metals. should be a good indicator of the rebuild level. anything from a bearing/seal refresh to a full overhaul of planetary/clutch/chain. you might be in the market for a lightly-used replacement if it comes to that. depends on your preference.

Pulled the fill plug before the drain plug and couldnt get the drain plug off. Ill need to enlist some assistance there. I did however add fluid to the transfer case and it was very low...took over a quart. After sitting it did not want to move. Sounds 100 X worse. I gently pulled it up into my driveway and the sound got better as It moved. I believe I have pump rub and the fluid ran out of my tcase. Im in the market for a transfer case. Thank goodness my husband works for LKQ...however he is not at all mechanically inclined. Ill probably have it towed to the shop after I get the new case.

 

[Chubbs]

You are on the right track. Good luck with it all

 

[JonnyTahoe]

Whoa, that’s the SUV equivalent of baseball card in the spokes.

When you say put in neutral, do you mean put transfer case in neutral or just tranny gear shift? Putting the transfer case into neutral will disengage it from the driveline. In that mode, you can lift up the rear making sure you chok the front so doesn’t roll, and turn the rear by hand and see if it still makes the noise. If it does, it could be your rear axle or main driveshaft. I do not know if the transmission is fully disconnected in this mode but I suspect it is not. Someone else might chime in who knows more but at least that is one method of isolating the components a little bit further . good luck

The Transfer Case has no Neutral Option.

 

[Malibu907]

You are on the right track. Good luck with it all

Okay so now transfer case is in...no more horrible noise. But when we tested 4wd my service 4wd came on and its now stuck in 4 hi. I kept the motor part from my other case so that I wouldn't have to flash it. Before all of this, even making noise it would go through all gears. Now I'm stuck in 4 hi. Any ideas?

 

[Chubbs]

transfer case motor, probably. there is a little sensor inside of it that can be replaced for $30-$40. the technical name is "encoder ring" or "encoder sensor"

I will post some links later. whenever the sensor goes out, the motor either will not shift or it shifts 1-time and gets stuck. you can pull the 4wd fuse, or sometimes it will let you change it after the truck has been turned off. very common problem

I'm about 90% sure on the position sensor above but the switch panel (buttons) in the dash are simple to check with a voltage meter to rule-out that part of it. There is a computer running everything in the dash behind the mode buttons; do a search on re-programming that thing. Search the web for a while, thousands of folks have had to do what you are now doing. I hate that you are having so many complications

you might also clean-up the contacts where the main socket is underneath the truck. I had a little bit of rain water from a puddle set mine on the fritz once upon a time.

https://www.oreillyauto.com/detail/...4250577/2003/gmc/yukon?q=encoder+sensor&pos=0

https://www.rockauto.com/en/moreinfo.php?pk=2002480&cc=1415551&jsn=611